Devices and methods for processing whole blood using flow rate stoppage phase

Abstract

To provide a device and a method for separating whole blood which include flowing whole blood to a centrifuge, separating whole blood within the centrifuge, and flowing separated blood components out of the centrifuge.SOLUTION: The device and method include a flow rate stoppage phase executed one or more times while the method is practiced. The flow rate stoppage phase includes: (i) stopping the flow of whole blood to the centrifuge and stopping the flow of separated blood components out of the centrifuge; (ii) spinning the centrifuge at a selected rate; and (iii) after a selected time, ending the flow rate stoppage phase and resuming the flow of whole blood to the centrifuge and the flow of separated blood components out of the centrifuge.SELECTED DRAWING: Figure 5C

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit and priority of U.S. Provisional Patent Application No. 63 / 300,895, filed on January 19, 2022, the content of which is incorporated herein by reference.

[0002] [Technical Field] The present disclosure generally relates to devices and methods for processing whole blood, and more particularly, to devices and methods for separating whole blood into red blood cell products and plasma products.

Background Art

[0003] It is well known to collect whole blood from donors using manual collection procedures such as a visit by the donor to a blood drive, blood center, or hospital. In such procedures, blood is typically collected by simply flowing it from the donor into a collection container (e.g., a flexible pouch or bag) under the forces of gravity and venous pressure. Various blood collection devices can be used to assist or facilitate the collection of blood or blood components.

[0004] The collection container in manual collection is often part of a larger pre - assembled arrangement of tubes and containers (sometimes called satellite containers) that are used for further processing of the collected whole blood. More specifically, whole blood is typically collected first into a so - called primary collection container that also contains an anticoagulant such as a solution of sodium citrate, phosphate, and glucose (''CPD''), among others (but not limited to these).

[0005] After the initial collection, it is common practice to transport the collected whole blood to another facility or location (sometimes called a "back lab") for further processing to separate red blood cells, platelets, and plasma. This may involve performing additional processes such as cell washing and the production and collection of plasma cryoprecipitate. This process typically requires manually loading the primary collection container and associated tubing and satellite containers into a centrifuge to separate the whole blood into concentrated red blood cells and platelet-rich or platelet-poor plasma. The separated components are then squeezed from the primary collection container into one or more satellite containers, and the red blood cells are combined with additives or preservatives pre-filled in one of the satellite containers. After the above steps, the blood components may be centrifuged again as needed, for example, to separate platelets from plasma. The entire process requires multiple large bed centrifuges and fluid squeezing devices. Due to the interaction of multiple operators, this process is laborious, time-consuming, and prone to human error.

[0006] Accordingly, efforts continue to automate the devices and systems used for post-collection processing of whole blood, and recently, the use of automated blood component separators for such post-collection processing has been proposed. The subject matter disclosed herein provides further advances in various embodiments of devices, systems, and methods that may be used in whole blood collection and post-collection processing systems by using continuous flow centrifugation in a system that utilizes a pre-programmed programmable control unit that automatically performs selected back-lab processes and can also be programmed by the user to meet the user's specific needs and requirements. [Overview of the project]

[0007] The subject matter of the present invention has several embodiments that may be embodied individually or together in the apparatus, systems, and methods described and / or claimed below. These embodiments may be used individually or in combination with other embodiments of the subject matter described herein, and the description of these embodiments together is not intended to preclude the use of these embodiments individually or the claim of such embodiments individually or in different set combinations, as described in the claims attached herein or later amended. For the purposes of this description and the claims, unless otherwise specified, “blood” means whole blood and blood components such as concentrated red blood cells, plasma, platelets, and white blood cells, with or without anticoagulants or additives.

[0008] The following summary is intended to inform the reader of various potential aspects of this subject matter and is non-limiting and non-exclusive with respect to various possible aspects or combinations of aspects. Additional embodiments and features may be found in the detailed description and / or accompanying drawings herein.

[0009] A method for separating whole blood is provided, comprising performing a priming step in which the pump system and valve system of a blood processing device are controlled to prime a processing chamber located within the centrifuge of the blood processing device. A blood separation step is performed in which the pump system, valve system and centrifuge are controlled to separate the blood in the processing chamber into at least two blood components. A blood component collection step is performed in which the pump system and valve system are controlled to collect at least a portion of one of the at least two blood components. A flow stop step is performed to interrupt at least one of the priming step, the blood separation step and the blood component collection step, and the flow stop step includes: (i) controlling the pump system and valve system to prevent the inflow and outflow of fluid into the processing chamber; (ii) controlling the centrifuge at a selected speed and / or a selected relative centrifugal force; (iii) ending the flow stop step after a selected time has elapsed; and (iv) resuming the interrupted step or proceeding to a subsequent step of the method after the end of the flow stop step.

[0010] In another embodiment, the blood processing device includes a pump system, a valve system, a centrifuge, and a control unit. The control unit is configured to perform a blood separation procedure which includes: performing a priming step in which the pump system and valve system are controlled to prepare a processing chamber located within the centrifuge; performing a blood separation step in which the pump system, valve system, and centrifuge are controlled to separate the blood in the processing chamber into at least two blood components; performing a blood component collection step in which the pump system and valve system are controlled to collect at least a portion of one of the at least two blood components; and performing a flow stop step to interrupt at least one of the priming step, the blood separation step, and the blood component collection step. The flow stop step includes: (i) controlling the pump system and valve system to prevent the flow of fluid into and out of the processing chamber; (ii) controlling the centrifuge at a selected speed and / or a selected relative centrifugal force; (iii) ending the flow stop step after a selected time has elapsed; and (iv) resuming the interrupted step or proceeding to the next step of the blood separation procedure after the end of the flow stop step.

[0011] These and other aspects of this subject matter are described in the following detailed description in the attached drawings. [Brief explanation of the drawing]

[0012] [Figure 1] This is a perspective view of an exemplary reusable hardware component of a blood processing system configured to accept a disposable fluid flow circuit.

[0013] [Figure 2] Figure 1 is a plan view of an exemplary disposable fluid flow circuit for use in combination with the durable hardware components.

[0014] [Figure 3] Figure 2 is a schematic diagram of the fluid flow circuit attached to the processing apparatus in Figure 1 in order to complete the blood processing system according to one aspect of this disclosure.

[0015] [Figure 4] FIG. 3 is a schematic diagram of a blood treatment system that executes the "blood priming" stage of an exemplary blood treatment procedure.

[0016] [Figure 5A] FIG. 3 is a schematic diagram of a blood treatment system that executes the "flow stop" stage of an exemplary blood treatment procedure.

[0017] [Figure 5B] FIG. is a flowchart showing an alternative example of logic or determination for starting / continuation of the flow stop stage.

[0018] [Figure 5C] FIG. is a flowchart showing another logic or determination for starting / continuation of the flow stop stage.

[0019] [Figure 6] FIG. 3 is a schematic diagram of a blood treatment system that executes the "separation establishment" stage of an exemplary blood treatment procedure.

[0020] [Figure 7] FIG. 3 is a schematic diagram of a blood treatment system that executes the "collection" stage of an exemplary blood treatment procedure in which separated red blood cells are leukoreduced before collection.

[0021] [Figure 8] FIG. 7 is a schematic diagram of a variation of the "collection" stage in which separated red blood cells are not leukoreduced before collection.

[0022] [Figure 9] FIG. 3 is a schematic diagram of a blood treatment system that executes the "red blood cell recovery" stage of an exemplary blood treatment procedure in which separated red blood cells are leukoreduced before collection.

[0023] [Figure 10]This is a schematic diagram of a modified version of the "red blood cell recovery" stage in Figure 9, in which the separated red blood cells are not reduced in leukopenia before collection.

[0024] [Figure 11] Figure 3 is a schematic diagram of a blood processing system performing the "additive solution flush" step of an exemplary blood processing procedure, in which the additive solution is guided through a leukopenic filter before entering the red blood cell collection container.

[0025] [Figure 12] This is a schematic diagram of a modified version of the “additive solution flush” stage in Figure 11, in which the additive solution enters the red blood cell collection container without passing through the leukopenia filter.

[0026] [Figure 13] Figure 3 is a schematic diagram of a blood processing system performing the "air removal" step of an exemplary blood processing procedure.

[0027] [Figure 14] Figure 3 is a schematic diagram of a blood processing system performing the "sealing" stage of an exemplary blood processing procedure. [Modes for carrying out the invention]

[0028] The embodiments disclosed herein are intended to provide an illustrative description of the subject matter. However, they are merely illustrative and not exclusive, and the subject matter of the invention can be embodied in various forms. Accordingly, the specific details disclosed herein should not be construed as limiting the subject matter as defined in the appended claims.

[0029] This disclosure relates to apparatus and methods for whole blood separation using a centrifuge. The apparatus and methods include one or more flow stop stages during any stage of the separation method. During a flow stop stage, the flow of whole blood to the centrifuge and the blood components separated from the centrifuge are stopped. While the flow of whole blood and separated components is stopped, the centrifuge rotates at a selected speed. For example, the centrifuge rotates at a speed between approximately 500 RPM and approximately 5500 RPM. In one alternative example, the centrifuge rotates at a speed between approximately 1500 RPM and approximately 5000 RPM. In yet another alternative example, the centrifuge rotates at a speed of approximately 1500 RPM, or approximately 3500 RPM, or approximately 5000 RPM. Independently of or in addition to the rotational speed, the relative centrifugal force (G) may be between approximately 10G and approximately 1450G. In other words, the relative centrifugal force may fall within this range regardless of the rotational speed or size of the centrifuge. In one alternative scenario, the relative centrifugal force may be approximately 100G, and in another, it may be approximately 1140G. Once the selected time has elapsed, the flow stop phase ends, the flow of blood and blood components to and from the centrifuge is resumed, and the separation process continues. For example, the selected time may be between approximately 15 seconds and approximately 45 seconds. In one alternative scenario, the selected time may be approximately 30 seconds.

[0030] The methods disclosed herein may be used with any suitable centrifugal blood separation system and / or process. The systems and processes described and shown in relation to Figures 1 to 14 are illustrative and provided for the purpose of illustrating and understanding the methods. Therefore, it will be understood that the methods are not limited to the blood separation systems and processes disclosed herein, and that the methods may be used with any suitable centrifugal blood separation system / process. Furthermore, the methods disclosed herein can be used to separate whole blood and collect its components such as red blood cells, plasma, and buffy coat. For example, in one alternative example, the methods can be used to separate whole blood into red blood cells and plasma. In another alternative example, the system can be used to separate whole blood into red blood cells, plasma, and buffy coat.

[0031] This method involves flowing whole blood from a blood source into a centrifuge and rotating the centrifuge to separate the whole blood into its components. Optionally, this method may also include one or more of the following stages: a blood priming stage, a separation establishment stage, a collection stage, an air removal stage, an additive solution flush stage, or any other suitable stage or process. Periodically, and at least once at any point in the method, a flow stop stage is initiated. In the flow stop stage, the inflow and outflow to the centrifuge is stopped, and the blood in the centrifuge is rotated at a desired rate for a desired time, further separating cells from the plasma fraction of the blood. The flow stop stage may also include stopping one or more pumps in a pump system and / or closing one or more valves in a valve system.

[0032] Referring here to Figure 1, Figure 1 shows a reusable or durable hardware component or processing unit of a configurable automated blood processing system or blood component manufacturing system, collectively denoted by reference numeral 10, while Figure 2 shows a disposable or single-use fluid flow circuit, collectively denoted by reference numeral 12, used in conjunction with the processing unit 10 to process collected whole blood. The illustrated processing unit 10 includes associated pumps, valves, sensors, displays, and other devices for configuring and controlling the fluid flow through the fluid flow circuit 12, as will be described in detail below. The blood processing system may be controlled by a control unit integrated with the processing unit 10, which includes a programmable microprocessor for automatically controlling the operation of pumps, valves, sensors, etc. The processing unit 10 may also include wireless communication capabilities that enable the transfer of data from the processing unit 10 to an operator's quality control system.

[0033] More specifically, the illustrated processing apparatus 10 includes a user input and output touchscreen 14, a pump station or system including a first pump 16 (e.g., for pumping whole blood), a second pump 18 (e.g., for pumping plasma), a third pump 20 (e.g., for pumping additive solutions), a centrifuge mounting station and drive unit 22 (which may be referred to herein as the “centrifuge”), and a valve system including any suitable type of valves such as clamps 24a–c. The touchscreen 14 not only allows interaction between the user and the processing apparatus 10 but also allows monitoring of procedural parameters such as flow rate, container weight, and pressure. The pumps 16, 18, and 20 (collectively referred herein as part of the “pump system” of the processing apparatus 10) are shown as peristaltic pumps that receive a tube or conduit and, depending on the procedure being performed, can move a fluid through the associated conduit at various speeds. An exemplary centrifuge mounting station / drive unit is seen in U.S. Patent No. 8,075,468 (see Figures 26–28), which is incorporated herein by reference. The clamps 24a-c (collectively referred to herein as part of the “valve system” of the processing apparatus 10) can open and close fluid paths through tubes or conduits, and at the completion of the procedure, an RF sealer may be incorporated to complete the heat sealing of the tubes or conduits positioned within the clamps to seal the tubes or conduits leading to the product container.

[0034] A sterile connection / docking device may also be incorporated into one or more clamps 24a-c. The sterile connection device can use any of several different operating principles. For example, known sterile connection devices and systems include a radiant energy system that melts the membrane facing the fluid flow conduit, as in U.S. Patent No. 4,157,723; a heated wafer system that uses a wafer to cut the tube segment while the ends are still molten or semi-molten and then thermally bond or join them, as in U.S. Patents No. 4,753,697, No. 5,158,630, and No. 5,156,701; and a system that uses a removable closure film or web sealed to the ends of the tube segment, as in U.S. Patent No. 10,307,582, for example. Alternatively, the sterile connection may be formed by compressing or pinching a sealed tube segment, heating and cutting the sealed end, and joining the tube to the similarly processed tube segment, as in U.S. Patents No. 10,040,247 and No. 9,440,396, for example. All of the above patents are incorporated in their entirety by reference. Other sterilization connection devices based on other operating principles may also be used without departing from the scope of this disclosure.

[0035] The processing apparatus 10 also includes hangers 26a-d (each which can be associated with a weighing scale) for suspending various containers of disposable fluid circuits 12. The hangers 26a-26d are preferably mounted on a vertically movable support 28 to improve the portability of the processing apparatus 10. An optical system, including a laser 30 and a photodetector 32, is associated with the centrifuge 22 to determine and control the position of interfaces between separated blood components within the centrifuge 22. An exemplary optical system is shown in U.S. Patent Application Publication No. 2019 / 0201916, which is incorporated herein by reference. An optical sensor 34 is also provided for optically monitoring one or more conduits entering and leaving the centrifuge 22.

[0036] The surface of the processing unit 10 includes a nesting module 36 for housing a flow control cassette 50 (Figure 2) of the fluid flow circuit 12 (described in more detail below). The cassette nesting module 36 is configured to accept various disposable cassette designs so that the system can be used to perform different types of processing. Embedded within the illustrated cassette nesting module 36 are four valves 38a-d (collectively referred to herein as part of the “valve system” of the processing unit 10) for opening and closing the fluid flow path in the flow control cassette 50, and three pressure sensors 40a-c that can measure the pressure at various locations in the fluid flow circuit 12.

[0037] Referring to Figure 2, the illustrated fluid flow circuit 12 includes a flow control cassette 50 and a plurality of vessels 42, 44, 46, and 48 (the processing chamber 52 and the centrifuge 22 may be collectively referred to as the “centrifuge assembly”), each containing a processing / separation chamber 52 configured to be housed inside a centrifuge 22, all interconnected by conduits or tubular segments to enable continuous flow centrifugation. The flow control cassette 50 delivers the fluid flow through three tubular loops 54, 56, and 58, each loop positioned to engage with a specific one of the pumps 16, 18, and 20. Conduits or tubular segments may extend through the cassette 50, or the cassette 50 may have pre-formed fluid channels that direct the fluid flow.

[0038] In the fluid flow circuit 12 shown in Figure 2, container 42 may be pre-filled with an additive solution, container 44 may be filled with whole blood and connected to the fluid flow circuit 12 at the time of use, container 46 may be an empty container for receiving red blood cells separated from whole blood, and container 48 may be an empty container for receiving plasma separated from whole blood. Figure 2 shows a whole blood container 44 (for example, configured as a blood pack unit) as a blood source, but as described in detail herein, the blood source may also be a living donor. The fluid flow circuit may optionally include an air trap 60 (Figure 3) through which whole blood flows before entering the separation chamber, and / or a leukopenic filter 62 through which red blood cells flow before entering the red blood cell collection container 46.

[0039] The processing chamber 52 can be pre-formed to a desired shape and configuration by injection molding from a rigid plastic material, as shown and described in U.S. Patent No. 6,849,039, which is incorporated herein by reference. The specific geometric shape of the processing chamber 52 may vary depending on the elements being separated, but this disclosure is not limited to the use of any particular chamber design. For example, it is within the scope of this disclosure that the processing chamber 52 may be configured to be formed from a material that is flexible rather than a material that is rigid overall. When the processing chamber 52 is generally formed from a flexible material, the shape of the processing chamber 52 depends on the centrifuge 22. An exemplary processing chamber and associated centrifuge formed from a flexible material is described in U.S. Patent No. 6,899,666, which is incorporated herein by reference.

[0040] According to this disclosure, the control unit of the processing apparatus 10 is pre-programmed to automatically operate the system to perform one or more standard blood processing procedures selected by the operator via input to the touchscreen 14, and is further configured to be programmed by the operator to perform additional blood processing procedures. The control unit can be pre-programmed to substantially automate a wide variety of procedures, including but not limited to the production of red blood cells and plasma from a single unit of whole blood (described in more detail herein), pooling of buffy coat, separation of buffy coat into plasma products (described in U.S. Patent Application Publication 2018 / 0078582 incorporated herein by reference), addition of glycerol to red blood cells, washing of red blood cells, washing of platelets, and pooling and separation of cryoprecipitate.

[0041] A pre-programmed blood processing procedure operates the system with pre-set flow rate and centrifugal force settings, and a programmable control unit may be further configured to receive operator input regarding one or more of the flow rate and centrifugal force in order to override the pre-programmed settings in a standard blood processing procedure.

[0042] Furthermore, the programmable control unit is configured to receive input from the operator via the touchscreen 14 for operating the system to perform non-standard blood processing procedures. More specifically, the programmable control unit may be configured to receive input for setting non-standard blood processing procedures, including flow rate and centrifugal force.

[0043] Collection of red blood cells and plasma products In the exemplary procedure, the processing apparatus 10 and the fluid flow circuit 12 can be used in combination to process whole blood units into erythrocyte products and plasma products according to the method disclosed herein. Figure 3 is a schematic diagram of the exemplary fluid flow circuit 12 attached to the processing apparatus 10, showing selected components of the fluid flow circuit 12 and selected components of the processing apparatus 10. Figures 4-14 show different stages of the exemplary procedure. As shown in Figures 3-14, one of the clamps 24b is not used for the production of erythrocyte products and plasma products (but can be used for other procedures), while other illustrated components of the processing apparatus 10 are used.

[0044] In this specification, this is referred to as the “blood priming” stage, and in the initial stage shown in Figure 4, selected components of the fluid flow circuit 12 are primed using blood from a blood source. This is in contrast to typical apheresis devices that use a separately provided fluid (e.g., anticoagulant or saline) to prepare the fluid flow circuit. The blood source is shown as a whole blood container 44 in Figure 4, but may instead be a living donor. Therefore, it should be understood that the term “whole blood” may refer to blood with or without anticoagulant fluid.

[0045] During the blood priming phase, whole blood is drawn from the blood source (whole blood container 44 in the embodiment of Figure 4) into the fluid flow circuit 12 through line L1 by the operation of the first pump 16 (which may be called the "whole blood pump"). Valve 38c is closed and the blood is guided through pressure sensor 40c to line L2. The blood passes through air trap 60, pressure sensor 40a (which measures the pressure in the processing chamber 52), and optical sensor 34 before flowing into the processing chamber 52 located in the centrifuge 22 of the processing device 10.

[0046] The centrifuge 22 may remain stationary during the blood priming phase, or it may be controlled by the control unit of the processing unit 10 to rotate at a low rotational speed (e.g., about 1,000 to 2,000 rpm). Rotating the centrifuge 22 during the blood priming phase may be advantageous to generate sufficient gravity to ensure that the air in the processing chamber 52 (including air already present in the processing chamber 52 as well as air moving into the processing chamber 52 from lines L1 and / or line L2 due to the blood flow) is forced towards the low-G (radially inward) walls of the processing chamber 52. Higher centrifuge rotational speeds, such as 4,500 rpm (required for steady-state separation, as described later), may be undesirable because air blockage (where air accumulates and cannot be pushed out of the processing chamber 52, causing a pressure increase) is more likely to occur at higher G forces.

[0047] Blood entering the processing chamber 52 moves towards the high-G (radially outward) wall of the processing chamber 52, and air moves towards the low-G wall. The plasma outlet port of the processing chamber 52 is associated with the low-G wall of the processing chamber 52, and as a result, most of the air is expelled from the processing chamber 52 through the plasma outlet port and associated line L3, although some air may also be expelled from the processing chamber 52 through the red blood cell outlet port associated with the high-G wall of the processing chamber 52.

[0048] Valves 38b and 38d are closed, the second pump 18 (sometimes called the "plasma pump") is activated, and the third pump 20 (sometimes called the "additive pump") is deactivated. In this configuration, the air exiting the processing chamber 52 is directed through the red blood cell outlet port, through the associated line L4 and pressure sensor 40b to line L5, and then to line L6. Valve 38a is open, and the air flowing through line L6 merges with the air flowing through line L3 (i.e., the air exiting the processing chamber 52 via the plasma outlet port). The mixed air flows through line L7 and the open clamp 24c and into the plasma collection container 48. In Figures 4-14, it should be understood that the arrows on the containers indicate the direction of fluid flow between the containers and the conduits connected to them, and the absence of an arrow indicates that no fluid flows through the respective conduit. For example, line L7 is shown connected to the top of the plasma collection container 48, and the downward arrow (as in Figure 4) represents the downward flow of fluid into the plasma collection container 48. In contrast, line L1 is shown connected to the bottom of the whole blood container 44, and the downward arrow (as in Figure 4) represents the downward flow of fluid out of the whole blood container 44.

[0049] The airflow exiting the processing chamber 52 through one of the outlet ports is monitored by an optical sensor 34, which determines the optical density of the fluid flow through the monitored line and can distinguish between air and non-air fluid in lines L3 and L4. When non-air fluid is detected in both lines L3 and L4, the control unit of the processing device 10 terminates the blood priming phase and proceeds to the next stage of the procedure. The amount of blood drawn from the blood source into the fluid flow circuit 12 during the blood priming phase varies depending on many factors (e.g., the amount of air in the fluid flow circuit 12), but can be approximately 50-100 mL. The blood priming phase can take approximately 1-2 minutes.

[0050] Referring to Figure 5A, as described above, the “flow stop phase” may be performed one or more times during the blood separation and collection process. Furthermore, the flow stop phase may be performed periodically during or after any stage of the separation and collection process. Optionally, the flow stop phase may be performed during or after the priming phase. During such a phase, the flow of whole blood to the centrifuge assembly (processing chamber 52 and centrifuge 22) is stopped, and the flow of fluid from the centrifuge assembly is stopped. The stopping of the flow may be achieved by stopping or deactivating one or more of the pumps 16, 18, and 20 of the pump system, and / or closing one or more of the valves 24a, 24c, and 38a-38d of the valve system. For example, in Figure 5A, pumps 16, 18, and 20 are stopped, and valves 24a, 24c, and 38a-38d are closed. This prevents whole blood from flowing into the centrifuge assembly and prevents fluids such as blood components from flowing out of the centrifuge assembly.

[0051] During the flow cessation phase, the centrifuge 22 is rotated at a selected speed and / or a selected centrifugal force (G). For example, the centrifuge rotates at a speed between approximately 500 RPM and approximately 5500 RPM. In one alternative example, the centrifuge rotates at a speed between approximately 1500 RPM and approximately 5000 RPM. In yet another alternative example, the centrifuge rotates at a speed of approximately 1500 RPM, or approximately 3500 RPM, or approximately 5000 RPM. Independently of the rotational speed, or in addition to the rotational speed, the relative centrifugal force can be between approximately 10G and approximately 1450G. In one alternative example, the relative centrifugal force may be 100G, and in another alternative example, it may be approximately 1140G. After the selected time has elapsed, the flow of blood and blood components to the centrifuge assembly is resumed, and the blood separation method continues. For example, when the selected time ends, the flow stop phase ends, and one or more of the pumps 16, 18, and 20 are activated, and one or more of the valves 24a, 24c, and 38a-38d are opened to restart the flow. When the flow restarts, the current phase may be restarted, or the process may move to the next phase. In one alternative example, the selected time may be between approximately 15 seconds and approximately 45 seconds. In another alternative example, the selected time may be approximately 30 seconds.

[0052] Figure 5B includes a flowchart showing one alternative decision tree for performing a flow stop phase or a periodic flow stop phase. At 70, one of the phases disclosed herein (priming, separation establishment, collection, etc.) is started or continued / restarted. At this point, the pump is activated / turned on and the centrifuge is also turned on. Moving to 72, if a predetermined time has elapsed since the start / continuation / restart of the phase, the flow stop phase 74 may be started / executed. Otherwise, if the predetermined time has not elapsed at 72, the phase continues to 70. In the flow stop phase, the pump is stopped, valves are closed as necessary, and the centrifuge is set to rotate at a selected RPM and / or relative centrifugal force. After the flow stop phase has started, at 76, it is determined whether a selected time has elapsed (such as one of the selected times described above). If "no", the flow stop phase continues at 74. Otherwise, if the selected time has elapsed, it is determined at 78 whether the termination condition has occurred. Such termination conditions include, but are not limited to, the completion of a selected number of flow stop stages, the processing of a specific amount of blood, or the completion of a stage. If no termination conditions are met, the stage restarts at 70 and the process is repeated as described above. If, however, a termination condition is met, the stage restarts at 80 without any further flow stop stages, or the next stage begins.

[0053] Figure 5C includes a flowchart showing an alternative decision tree for performing the flow stop phase. At 82, the phase is started or continued / restarted. At this point, the pump is activated / turned on, and the centrifuge is also turned on. Proceeding to 84, it is determined whether the flow stop conditions are met. Such flow stop conditions include, but are not limited to, the start or end of a phase (priming, establishment, collection), that a certain amount of blood has been processed during the phase, or optical measurements of the centrifuge outlet line indicating the presence of unwanted fluid (e.g., platelets in the PPP line). If the flow stop conditions are met, it is possible to start / perform the flow stop phase 86. Otherwise, if the conditions are not met, the phase proceeds to 82. In the flow stop phase, the pump is stopped, valves are closed as needed, and the centrifuge is set to rotate at the selected RPM and / or relative centrifugal force. After the flow stop phase has started, at 88, it is determined whether the selected time has elapsed. If "no", the flow stop phase continues at 86. Otherwise, if the selected time has elapsed, the stage will restart, or a new stage will begin at 82, and the process will be repeated as described above.

[0054] The next stage (shown in Figure 6) is referred to herein as the “separation establishment” stage. When non-air fluid is detected in lines L3 and L4, the rotation speed of the centrifuge 22 is increased to a speed sufficient to separate the blood into packed red blood cells and platelet-poor plasma (for example, it may be in the range of approximately 4500–5500 rpm). To produce a platelet-poor plasma product, it may be advantageous for the processing chamber 52 to be configured with a plasma outlet port located downstream of the blood inlet port at a distance from the blood inlet port, rather than being located adjacent to the blood inlet port. Such a configuration allows platelets to settle into a separate layer between the plasma and red blood cells (commonly called the “buffy coat”) before the plasma is removed from the processing chamber 52, and thus the separated plasma can be made platelet-depleted. As for the whole blood pump 16, it continues to operate, but no additional blood is drawn from the blood source into the fluid flow circuit 12 during the separation establishment stage (as described later).

[0055] Since the blood source contains only a single unit of whole blood (approximately 500 mL) (in the case of a whole blood container) or is provided (in the case of a living donor), the system must operate with a finite volume of fluid. To avoid product loss or quality issues, the plasma and red blood cells, which are initially separated from the blood in processing chamber 52 and then removed from processing chamber 52, are mixed together to form recombined whole blood, rather than being sent to their respective collection containers, and are then recirculated back to processing chamber 52.

[0056] More specifically, during the separation establishment phase, the separated plasma exits the processing chamber 52 via the plasma outlet port and associated line L3. During this phase, the clamp 24c is closed, but the valve 38a remains open, allowing the plasma to flow from line L3 to line L6. The separated red blood cells exit the processing chamber 52 via the red blood cell outlet port and associated line L4. In the illustrated embodiment, there is no pump associated with line L4, and the red blood cells are discharged from the processing chamber 52 at a rate equal to the difference between the rate of the whole blood pump 16 and the rate of the plasma pump 18. In alternative embodiments, there may be a pump associated with the red blood cell outlet line instead of the plasma outlet line, or a first pump associated with the plasma outlet line and a second pump associated with the red blood cell outlet line.

[0057] The additive pump 20 is not operating at this stage, thereby directing red blood cells from line L4 to line L5. The plasma flowing through line L6 mixes with the red blood cells flowing through line L5 at the confluence of the two lines L5 and L6 to form recombined whole blood. Valve 38d is closed, directing the recombined whole blood to line L8. Valve 38b is also closed, thereby sending the recombined whole blood from line L8 to line L9, through the open valve 38c. The whole blood pump 16 draws the recombined whole blood from line L9 to line L2 (rather than drawing additional blood from the blood source into the fluid flow circuit 12), and the recombined blood passes through the air trap 60, pressure sensor 40a, and optical sensor 34 before flowing back into the processing chamber 52, where it is separated again into plasma and red blood cells.

[0058] The separation establishment phase continues until steady-state separation is achieved, which may take approximately 1-2 minutes. As used herein, the term “steady-state separation” means that the radial position of the interface between the separated components within the processing chamber 52 is maintained at least substantially (rather than moving radially inward or outward), and the blood is separated into its components within the processing chamber 52. The interface position may be determined and controlled according to any suitable approach, including the use of an interface detector of the type described in U.S. Patent Application Publication No. 2019 / 0201916.

[0059] Steady-state separation is preferably achieved by the interface between separated components at a target position within the processing chamber 52. The target position may correspond to the interface position where separation efficiency is optimized, but the exact position varies depending on many factors (e.g., whole blood hematocrit). However, in exemplary embodiments, the target position of the interface may be the position of the interface when red blood cells occupy approximately 52% of the thickness or width (radially) of the channel defined by the processing chamber 52. In the illustrated embodiment, the position of the interface within the processing chamber 52 can be adjusted by changing the flow rate of the plasma pump 18, increasing the flow rate to draw more separated plasma from the processing chamber 52 (thus reducing the thickness of the plasma layer within the processing chamber 52) and moving the interface toward the low-G wall, or decreasing the flow rate to draw less plasma from the processing chamber 52 (thus increasing the thickness of the plasma layer within the processing chamber 52) and moving the interface toward the high-G wall.

[0060] In an exemplary procedure, the control unit of the processing unit 10 controls the whole blood pump 16 to operate at a constant speed, and the plasma pump 18 initially operates at the same speed, which rapidly increases the thickness of the red blood cell layer in the processing chamber 52, moving the interface toward the low-G wall. As the thickness of the red blood cell layer increases and the interface approaches the target position, the speed of the plasma pump 18 is gradually reduced. As described above, the target position of the interface may depend on the hematocrit of the whole blood. This means that the speed of the plasma pump 18 (which controls the position of the interface) may also depend on the hematocrit of the whole blood. In one embodiment, this relationship can be expressed as follows:

[0061] Theoretical plasma pump velocity = whole blood pump velocity - ((whole blood hematocrit × whole blood pump velocity) / hematocrit of separated red blood cells) [Equation 1]

[0062] The hematocrit of whole blood can be measured by the optical sensor 34 before or during the procedure, while the hematocrit of separated red blood cells can be determined by the optical sensor 34 monitoring line L4 during the procedure. In practice, once an interface is located at the target position and steady-state separation is achieved, the plasma pump velocity does not usually remain at the theoretical velocity, but rather tends to "fluctuate" around the theoretical velocity.

[0063] Referring back to Figure 5A, optionally, one or more flow stop stages may be performed during the separation establishment stage. During such a stage, the flow of whole blood to the centrifuge assembly (processing chamber 52 and centrifuge 22) is stopped, and the flow of fluid from the centrifuge assembly is stopped. The stopping of flow may be achieved by stopping or deactivating one or more of the pumps 16, 18 and 20 of the pump system, and / or by closing one or more of the valves 24a, 24c and 38a-38d of the valve system.

[0064] During the flow cessation phase, the centrifuge 22 is rotated at a selected speed and / or a selected relative centrifugal force. For example, the centrifuge rotates at a speed between approximately 500 RPM and approximately 5500 RPM. In one alternative example, the centrifuge rotates at a speed between approximately 500 RPM and approximately 5500 RPM. In another alternative example, the centrifuge rotates at a speed between approximately 1500 RPM and approximately 5000 RPM. In yet another alternative example, the centrifuge rotates at a speed of approximately 1500 RPM, or approximately 3500 RPM, or approximately 5000 RPM. Independently of the rotational speed, or in addition to the rotational speed, the relative centrifugal force can be between approximately 10G and approximately 1450G. In one alternative example, the relative centrifugal force may be 100G, and in another alternative example, it may be approximately 1140G. After the selected time has elapsed, the flow of blood and blood components to the centrifuge assembly is resumed and the method continues. For example, when the selected time ends, the flow stop phase ends, one or more of the pumps 16, 18, and 20 are activated, and one or more of the valves 24a, 24c, and 38a-38d are opened to restart the flow. When the flow restarts, the separation establishment phase may restart, or the procedure may move to the next phase. In one alternative example, the selected time may be between approximately 15 seconds and approximately 45 seconds. In another alternative example, the selected time may be approximately 30 seconds.

[0065] Regardless of the specific method by which the control unit of the processing unit 10 performs the separation establishment phase to reach steady-state separation, once steady-state separation is established, the control unit terminates the separation establishment phase and proceeds to the “collection” phase shown in Figure 7 below. At the start of the collection phase, the centrifuge 22, whole blood pump 16, and plasma pump 18 all continue to operate at the same speed they were operating at at the end of the separation establishment phase. However, the valve system of the processing unit 10 is adjusted to draw additional blood from the blood source into the fluid flow circuit 12 until a total of one unit of whole blood has been drawn into the fluid flow circuit 12, while guiding the separated plasma and red blood cells into their respective collection containers (rather than recombining them and recirculating them through the centrifuge 22).

[0066] More specifically, during the collection phase, valve 38c is closed, which causes the whole blood pump 16 to draw additional blood from the blood source (in the illustrated embodiment, this is a whole blood container 44, but may be a living donor) into line L1. The whole blood pump 16 draws the blood from the blood source into line L1 and then into line L2, and the blood passes through the air trap 60, pressure sensor 40a, and optical sensor 34 before flowing into the processing chamber 52, where it is separated into plasma and red blood cells. Most of the platelets in the whole blood remain in the processing chamber 52 along with some white blood cell populations (such as mononuclear cells), but larger white blood cells such as granulocytes may be expelled along with the concentrated red blood cells.

[0067] The separated plasma exits the processing chamber 52 via the plasma outlet port and associated line L3. Valve 38a is closed, directing the plasma from line L3 to line L7 and through the open clamp 24c to the plasma collection container 48.

[0068] The separated red blood cells exit the processing chamber 52 via the red blood cell exit port and associated line L4. The additive pump 20 is operated by the control unit to draw the additive solution (in one exemplary embodiment, ADSOL®, but other red blood cell additives may be used) from the additive solution container 42 via line L10. The red blood cells flowing through line L4 are mixed with the additive solution flowing through line L10 at the confluence of the two lines L4 and L10, forming a mixture that flows into line L5 and continues to flow through line L5. The mixture is eventually led to the red blood cell collection container 46, but may first be transported through a leukopenic filter 62 (if provided), as shown in Figure 7. Even if a leukopenic filter 62 is provided, the valve system can be controlled so that the mixture bypasses the leukopenic filter 62 and enters the red blood cell collection container 46 without reducing the number of white blood cells, as shown in Figure 8. It is also within the scope of this disclosure that the mixture is sent through the leukopenic filter 62 at the start of the collection phase so that only a portion of the collected red blood cells are leukopenic, and that the valve system is reconfigured during the collection phase so that the mixture bypasses the leukopenic filter 62.

[0069] In the configuration shown in Figure 7 (where the mixture is leukopenicated), valves 38a, 38b, and 38c are closed, while valve 38d is open, allowing the mixture to flow from line L5 to line L11. The mixture then flows through the open valve 38d and the leukopenication filter 62 to line L12. The leukopenicated mixture then flows through the open clamp 24a into the red blood cell collection container 46.

[0070] In the configuration shown in Figure 8 (where the mixture is not leukopenic), valves 38a, 38c, and 38d are closed, but valve 38b is open, allowing the mixture to flow from line L5 to line L8 and then to line L13. The mixture flows through the open valve 38b to line L12, bypassing the leukopenic filter 62. The non-leukopenic mixture then flows through the open clamp 24a into the red blood cell collection container 46.

[0071] As described above, the mixture can pass through the leukopenic filter 62 at the start of the collection phase (as shown in Figure 7), and during the collection phase, the valve system can be reconfigured so that the mixture bypasses the leukopenic filter 62 (as shown in Figure 8), so that only a portion of the collected red blood cells are leukopenic. In one embodiment, a pressure sensor 40b monitors the pressure of the leukopenic filter 62. If the pressure sensor 40b detects that the pressure of the leukopenic filter 62 has risen above a predetermined pressure threshold (which may indicate filter clogging), the control unit can reconfigure the valve system (from the configuration in Figure 7 to the configuration in Figure 8) so that the mixture bypasses the leukopenic filter 62. The system can then warn the operator that the red blood cell product is not leukopenic.

[0072] Regardless of whether the collected red blood cells are leukopenic (or partially leukopenic), the collection phase continues until one unit of whole blood is drawn from the blood source into the fluid flow circuit 12. If a whole blood container 44 is used as the blood source (as in the illustrated embodiment), the collection phase ends when the whole blood container 44 (from which one unit of whole blood is initially supplied) is empty, and different approaches to this may be employed to determine when the whole blood container 44 is empty. For example, in one embodiment, a pressure sensor 40c monitors the hydrostatic pressure of the whole blood container 44. An empty whole blood container 44 may be detected when the hydrostatic pressure measured by the pressure sensor 40c is below a threshold. Alternatively (or additionally), the weight of the whole blood container 44 can be monitored by a weighing scale, and an empty whole blood container 44 is detected when the weight is below a threshold. In the case of a living donor (or when multiple units of blood are supplied to the whole blood container 44), the volumetric flow rate of the whole blood pump 16 can be used to determine when one unit of whole blood has been drawn into the fluid flow circuit 12.

[0073] Referring back to Figure 5A, optionally, one or more flow stop phases may be performed during the collection phase. During such phases, the flow of whole blood to the centrifuge assembly (processing chamber 52 and centrifuge 22) is stopped, and the flow of fluid from the centrifuge assembly is stopped. Flow stopping may be achieved by stopping or deactivating one or more of the pumps 16, 18 and 20 of the pump system, and / or by closing one or more of the valves 24a, 24c and 38a-38d of the valve system.

[0074] During the flow cessation phase, the centrifuge 22 is rotated at a selected speed and / or a selected relative centrifugal force. For example, the centrifuge rotates at a speed between approximately 500 RPM and approximately 5500 RPM. In one alternative example, the centrifuge rotates at a speed between approximately 1500 RPM and approximately 5000 RPM. In yet another alternative example, the centrifuge rotates at a speed of approximately 1500 RPM, or approximately 3500 RPM, or approximately 5000 RPM. Independently of the rotational speed, or in addition to the rotational speed, the relative centrifugal force (G) can be between approximately 10G and approximately 1450G. In one alternative example, the relative centrifugal force may be 100G, and in another alternative example, it may be approximately 1140G. After the selected time has elapsed, the flow of blood and blood components to the centrifuge assembly is resumed, and the method continues. For example, when the selected time ends, the flow stop phase ends, one or more of pumps 16, 18, and 20 are activated, and one or more of valves 24a, 24c, and 38a-38d are opened to restart the flow. When the flow restarts, the collection phase may resume, or the procedure may move to the next phase. In one alternative example, the selected time may be between approximately 15 and 45 seconds. In another alternative example, the selected time may be approximately 30 seconds.

[0075] Once a total of one unit of whole blood has been drawn into the fluid flow circuit 12, the control unit moves the procedure to the "red blood cell retrieval" stage shown in Figure 9. In the red blood cell retrieval stage, air from the plasma collection container 48 (transported during the blood priming stage) is used to retrieve the contents of the processing chamber 52 (which may mainly consist of red blood cells) and reduce product loss.

[0076] In the illustrated embodiment, the whole blood pump 16 is stopped, while the plasma pump 18 is operated in the reverse direction (relative to the direction of operation up to this stage of the procedure). This draws air from the plasma collection container 48 into line L7. Valve 38a is closed, while clamp 24c is open, allowing air to flow through line L7 into line L3, and through line L3 into the processing chamber 52 via the plasma outlet port. As the air flows through the plasma outlet port, it enters the low-G side of the processing chamber 52. Once additional air is introduced into the processing chamber 52, the air moves from the low-G wall to the high-G wall, and thus the liquid contents move through the red blood cell outlet port on the high-G side into line L4. During this stage, the centrifuge 22 may be operated at a slower speed (e.g., in the range of about 1,000 to 2,000 rpm) to reduce the risk of air blockage (as during the blood priming stage).

[0077] The additive pump 20 continues to operate, drawing the additive solution from the additive solution container 42 through line L10 and mixing it with the contents of the processing chamber 52 flowing through line L4 at the confluence of the two lines L4 and L10. The mixture flows into line L5 and continues to flow through line L5. If the valve system is configured as shown in Figure 7 at the end of the collection phase (to direct the flow to the leukopenia filter 62), valves 38a, 38b, and 38c are kept closed and valve 38d is kept open, sending the mixture to line L11 for leukopenia, as shown in Figure 9. On the other hand, if the valve system is configured as shown in Figure 8 at the end of the collection phase (to bypass the leukopenia filter 62), valves 38a, 38c, and 38d can be kept closed and valve 38b is opened, directing the mixture through lines L8 and L13 and bypassing the leukopenia filter 62, as shown in Figure 10. As described above regarding the collection stage, the control unit can stop the leukopenia of the mixture during the red blood cell collection stage by changing the configuration of the valve system from the configuration shown in Figure 9 to the configuration shown in Figure 10 (for example, if the pressure of the leukopenia filter 62 becomes too high).

[0078] Regardless of whether the mixture is filtered, it flows into line L12 and into the red blood cell collection container 46 through the open clamp 24a. The red blood cell collection stage continues until all air is removed from the plasma collection container 48. In one exemplary embodiment, the weight of the plasma collection container 48 can be monitored by a weighing scale, and an empty plasma collection container 48 is detected when the weight is below a threshold. Other approaches can also be used to determine when to terminate the red blood cell collection stage, such as using an optical sensor 34 to detect plasma flowing through line L3.

[0079] Referring back to Figure 5A, optionally, a flow stop phase may be performed one or more times during the red blood cell recovery phase. During such a phase, the flow of whole blood to the centrifuge assembly (processing chamber 52 and centrifuge 22) is stopped, and the flow of fluid from the centrifuge assembly is stopped. The stopping of the flow may be achieved by stopping or halting one or more of the pumps 16, 18 and 20 of the pump system, and / or by closing one or more of the valves 24a, 24c and 38a-38d of the valve system.

[0080] During the flow cessation phase, the centrifuge 22 is rotated at a selected speed and / or a selected relative centrifugal force. For example, the centrifuge rotates at a speed between approximately 500 RPM and approximately 5500 RPM. In one alternative example, the centrifuge rotates at a speed between approximately 1500 RPM and approximately 5000 RPM. In yet another alternative example, the centrifuge rotates at a speed of approximately 1500 RPM, or approximately 3500 RPM, or approximately 5000 RPM. Independently of the rotational speed, or in addition to the rotational speed, the relative centrifugal force can be between approximately 10G and approximately 1450G. In one alternative example, the relative centrifugal force may be 100G, and in another alternative example, it may be approximately 1140G. After the selected time has elapsed, the flow of blood and blood components to the centrifuge assembly is resumed, and the method continues. For example, when the selected time ends, the flow stop phase ends, one or more of pumps 16, 18, and 20 are activated, and one or more of valves 24a, 24c, and 38a-38d are opened to restart the flow. Once the flow is restarted, the red blood cell recovery phase may resume, or the procedure may move to the next phase. In one alternative example, the selected time may be between approximately 15 seconds and approximately 45 seconds. In another alternative example, the selected time may be approximately 30 seconds.

[0081] Once the red blood cell retrieval stage is complete, the procedure moves to the "additive solution flush" stage. In the additive solution flush stage, the additive solution from the additive solution container 42 is transported into the red blood cell collection container 46 until a target amount of additive solution is present in the red blood cell collection container 46. The only change in the transition from the red blood cell retrieval stage to the additive solution flush stage is to stop the plasma pump to prevent plasma from being removed from the plasma collection container 48 (although it is also possible to operate the additive pump 20 at a different speed). Thus, if the valve system is configured to direct the flow through the leukopenic filter 62 at the end of the red blood cell retrieval stage (as shown in Figure 9), the additive solution flush stage will proceed as shown in Figure 11. On the other hand, if the valve system is configured to bypass the leukopenic filter 62 at the end of the red blood cell retrieval stage (as shown in Figure 10), the additive solution flush stage will proceed as shown in Figure 12. If the additive solution is pumped through the leukopenic filter 62 during the additive solution flushing stage (as shown in Figure 11), the additive solution flowing through line L11 will flush out any remaining red blood cells in the leukopenic filter 62 into the red blood cell collection container 46 (in addition to achieving an appropriate amount of additive solution relative to the red blood cell product).

[0082] The additive solution flushing stage continues until a target amount of additive solution has been added to the red blood cell collection container 46. In one exemplary embodiment, the weight of the additive solution container 42 can be monitored by a weighing scale, and a specific change in weight corresponds to the target amount of additive solution delivered to the red blood cell collection container 46. Alternatively (or additionally), the weight of the red blood cell collection container 46 may be monitored by a weighing scale, with a specific change in weight corresponding to the target amount of additive solution delivered to the red blood cell collection container 46.

[0083] Once the additive solution flushing stage is complete, the system moves to the “air evacuation” stage, as shown in Figure 13. During the air evacuation stage, the red blood cell collection container 46 is “burped” to remove all residual air for storage (just as air was removed from the plasma collection container 48 during the red blood cell collection stage). This is done by reversing the direction of operation of the additive pump 20, closing valve 38d (if it is not already closed at the end of the additive solution flushing stage), and opening valve 38b (if it is not already open at the end of the additive solution flushing stage). The additive pump 20 draws air from the red blood cell collection container 46 through line L12 and open clamp 24a to line L13, and through open valve 38b. The air travels through lines L8, L5, and L10 and finally reaches the additive solution container 42. Figure 13 shows that air is discharged from the red blood cell collection container 46 to the additive solution container 42, but it is also within the scope of this disclosure that all or part of the air may be directed to different locations in the fluid flow circuit 12 (for example, to the processing chamber 52 and / or into the whole blood container 44, if one is provided).

[0084] The air removal stage continues until all air is removed from the red blood cell collection container 46, which can be determined by detecting a change in the weight of the red blood cell collection container 46 (e.g., a change in weight) (e.g., using a weighing scale).

[0085] Once the air venting stage is complete, any of several post-processing stages can be performed. For example, Figure 14 shows the “seal” stage, where all clamps and valves are closed and all pumps are stopped. Line L12 connected to the red blood cell collection container 46 and line L7 connected to the plasma collection container 48 are sealed and optionally cut for storage of plasma and red blood cell products. If lines L7 and L12 are cut, the plasma collection container 48 and red blood cell collection container 46 can be stored, but the rest of the fluid flow circuit 12 is discarded. Lines L7 and L12 can be sealed (and optionally cut) according to any suitable method, including being sealed by an RF sealer incorporated into or associated with clamps 24a and 24c, for example. In another embodiment, lines L7 and L12 can be sealed (and optionally cut) using a dedicated sealing device to remove the fluid flow circuit 12 from the processing unit 10.

[0086] manner Embodiment 1. A blood processing apparatus comprising a pump system, a valve system, a centrifuge, and a control unit, wherein the control unit is configured to perform a blood separation procedure including: performing a priming step in which the pump system and the valve system are controlled to prime a processing chamber located within the centrifuge; performing a blood separation step in which the pump system, the valve system, and the centrifuge are controlled to separate the blood in the processing chamber into at least two blood components; performing a blood component collection step in which the pump system and the valve system are controlled to collect at least a portion of one of the at least two blood components; and performing a flow stop step that obstructs at least one of the priming step, the blood separation step, and the blood component collection step, wherein the flow stop step includes (i) controlling the pump system and the valve system to obstruct the fluid flow in and out of the processing chamber; (ii) controlling the centrifuge at a selected speed and / or a selected relative centrifugal force; (iii) ending the flow stop step after a selected time; and (iv) restarting the step that was obstructed after the end of the flow stop step, or proceeding to a subsequent step of the blood separation procedure.

[0087] Embodiment 2. The blood processing apparatus according to Embodiment 1, wherein the blood includes whole blood, and at least two blood components include red blood cells and plasma.

[0088] Embodiment 3. The blood processing apparatus according to Embodiment 1 or 2, wherein controlling the centrifuge at a selected speed during the flow rate stop phase includes rotating at a speed between 500 RPM and 5500 RPM.

[0089] Embodiment 4. A blood processing apparatus according to any one of Embodiments 1 to 3, wherein controlling the centrifuge at a selected speed during the flow rate stop phase includes rotating at a speed of approximately 1500 RPM, approximately 3500 RPM, or approximately 5000 RPM.

[0090] Embodiment 5. A blood processing apparatus according to any one of Embodiments 1 to 4, wherein the selected time for the flow rate stop phase includes a period of 15 to 45 seconds.

[0091] Embodiment 6. A blood processing apparatus according to any one of Embodiments 1 to 5, wherein the selected time for the flow rate stop phase includes approximately 30 seconds.

[0092] Embodiment 7. The blood processing apparatus according to any one of Embodiments 1 to 6, wherein the blood component collection step further includes (i) transporting whole blood from the blood source to the processing room until the entire volume of one unit of whole blood is transported from the blood source to the processing room, and (ii) controlling a centrifuge to separate the whole blood in the processing room into plasma and red blood cells, the separated plasma being transported from the processing room to a plasma collection container, the separated red blood cells being transported out of the processing room, the additive solution being transported out of the additive solution container of the fluid flow circuit, and the separated red blood cells and additive solution being combined as a mixture and transported into the red blood cell collection container of the fluid flow circuit.

[0093] Embodiment 8. The blood processing apparatus according to Embodiment 7, further comprising performing an additive solution flush step in which the additive solution is transported from an additive solution container to a red blood cell collection container using a pump system and a valve system until a target amount of additive solution is transported into a red blood cell collection container.

[0094] Embodiment 9. A blood processing apparatus according to any one of Embodiments 7 to 8, wherein the fluid flow circuit includes a whole blood container for containing one unit of whole blood, and the blood source is the whole blood container.

[0095] Embodiment 10. A blood processing apparatus according to any one of Embodiments 7 to 9, wherein performing a blood component collection step includes measuring the weight of a whole blood container and terminating the blood component collection step based at least in part on the weight of the whole blood container.

[0096] Embodiment 11. The blood processing apparatus according to Embodiment 10, wherein the blood source is a living donor.

[0097] Embodiment 12. A blood processing apparatus according to any one of Embodiments 7 to 11, wherein performing a blood component collection step further includes measuring the hydrostatic pressure of a whole blood container and terminating the blood component collection step at least in part based on the hydrostatic pressure of the whole blood container.

[0098] Embodiment 13. A blood processing apparatus according to any one of Embodiments 7 to 11, wherein performing a blood component collection step includes, during at least a portion of the blood component collection step, transporting the mixture through a leukopenic filter before it is brought into a red blood cell collection container.

[0099] Embodiment 14. A blood processing apparatus according to any one of Embodiments 2 to 13, wherein the priming step comprises transporting whole blood from a blood source to a processing chamber in order to remove air from the processing chamber.

[0100] Embodiment 15. A blood processing apparatus according to any one of embodiments 1 to 14, wherein performing a priming step includes monitoring the fluid leaving the processing chamber and terminating the priming step when it is detected that a non-air fluid has left the processing chamber.

[0101] Embodiment 16. A blood processing apparatus according to any one of Embodiments 2 to 15, wherein the blood separation step includes transporting the separated plasma and red blood cells out of the processing room, recombining the plasma and red blood cells as recombined whole blood, and transporting the recombined whole blood into the processing room.

[0102] Embodiment 17. A blood processing apparatus according to any one of embodiments 1 to 16, further comprising performing an air flush step using a pump system and valve system through which air is delivered to a processing chamber in order to remove at least one of the separated blood components from the processing chamber.

[0103] Embodiment 18. A blood processing apparatus according to any one of embodiments 1 to 17, wherein the pump system comprises a plurality of pumps and performs a flow stop step which includes stopping one or more of the plurality of pumps.

[0104] Embodiment 19. A blood processing apparatus according to any one of embodiments 1 to 18, wherein the valve system comprises a plurality of clamps and performs a flow stop step which includes closing one or more of the plurality of clamps.

[0105] Embodiment 20. A blood processing apparatus according to any one of embodiments 1 to 19, wherein the selected relative centrifugal force is between approximately 10G and approximately 1450G.

[0106] Embodiment 21. A blood processing apparatus according to any one of Embodiments 1 to 20, wherein the selected relative centrifugal force is between approximately 100G and approximately 1140G.

[0107] Embodiment 22. A method for separating whole blood, comprising: performing a priming step in which a pump system and valve system of a blood processing device are controlled to prime a processing chamber located within a centrifuge of the blood processing device; performing a blood separation step in which a pump system, valve system and centrifuge are controlled to separate the blood in the processing chamber into at least two blood components; performing a blood component collection step in which a pump system and valve system are controlled to collect at least a portion of one of the at least two blood components; and performing a flow stop step which interrupts at least one of the priming step, the blood separation step and the blood component collection step, wherein the flow stop step comprises (i) controlling the pump system and valve system to interrupt the fluid flow in and out of the processing chamber; (ii) controlling the centrifuge at a selected speed and / or a selected relative centrifugal force; (iii) ending the flow stop step after a selected time; and (iv) restarting the step that was interrupted after the end of the flow stop step or proceeding to a subsequent step of the method.

[0108] Embodiment 23. The method according to Embodiment 22, wherein the blood includes whole blood and at least two blood components include red blood cells and plasma.

[0109] Embodiment 24. The method according to Embodiment 22 or 23, wherein controlling the centrifuge at a selected speed during the flow stop phase includes rotating at a speed between 500 RPM and 5500 RPM.

[0110] Embodiment 25. The method according to any one of Embodiments 22 to 24, wherein controlling the centrifuge at a selected speed during the flow stop phase includes rotating at a speed of about 1500 RPM, about 3500 RPM, or about 5000 RPM.

[0111] Embodiment 26. The method according to any one of Embodiments 22 to 25, wherein the selected time for the flow rate stop phase is between 15 and 45 seconds.

[0112] Embodiment 27. The method according to any one of Embodiments 22 to 26, wherein the selected time for the flow rate stop phase includes approximately 30 seconds.

[0113] Embodiment 28. The method according to any one of Embodiments 23 to 27, wherein the blood component collection step further includes (i) transporting whole blood from the blood source to the processing room until the entire volume of one unit of whole blood is transported from the blood source to the processing room, and (ii) controlling a centrifuge to separate the whole blood in the processing room into plasma and red blood cells, the separated plasma being transported from the processing room to a plasma collection container, the separated red blood cells being transported out of the processing room, the additive solution being transported out of the additive solution container of the fluid flow circuit, and the separated red blood cells and additive solution being combined as a mixture and transported into the red blood cell collection container of the fluid flow circuit.

[0114] Embodiment 29. The method of Embodiment 28, further comprising performing an additive solution flush step using a pump system and a valve system, in which the additive solution is transported from the additive solution container to the red blood cell collection container until a target amount of the additive solution is transported into the red blood cell collection container.

[0115] Embodiment 30. The method according to Embodiment 28 or 29, wherein the fluid flow circuit includes a whole blood vessel containing one unit of whole blood, and the blood source is the whole blood vessel.

[0116] Embodiment 31. The method according to any one of Embodiments 28 to 30, wherein performing the blood component collection step includes measuring the weight of the whole blood container and terminating the blood component collection step based at least in part on the weight of the whole blood container.

[0117] Embodiment 32. The blood processing apparatus according to Embodiment 31, wherein the blood source is a living donor.

[0118] Embodiment 33. The method according to any one of embodiments 28 to 32, wherein performing the blood component collection step further includes measuring the hydrostatic pressure of the whole blood container and terminating the blood component collection step at least in part based on the hydrostatic pressure of the whole blood container.

[0119] Embodiment 34. The method according to any one of Embodiments 28 to 33, wherein performing the blood component collection step includes, during at least part of the blood component collection step, transporting the mixture through a leukopenic filter before transferring it to a red blood cell collection container.

[0120] Embodiment 35. The method according to any one of Embodiments 23 to 34, wherein the priming step comprises transporting whole blood from a blood source to a processing chamber in order to remove air from the processing chamber.

[0121] Embodiment 36. The method according to any one of Embodiments 22 to 35, wherein performing the priming step includes monitoring the fluid leaving the processing chamber and terminating the priming step when it is detected that a non-air fluid is leaving the processing chamber.

[0122] Embodiment 37. The method according to any one of Embodiments 23 to 36, wherein the blood separation step includes removing the separated plasma and red blood cells from the processing room, recombining the plasma and red blood cells as recombined whole blood, and bringing the recombined whole blood into the processing room.

[0123] Embodiment 38. The method according to any one of embodiments 22 to 37, further comprising performing an air flush step using a pump system and valve system through which air is delivered to a processing chamber in order to remove at least one of the separated blood components from the processing chamber.

[0124] Embodiment 39. The method according to any one of embodiments 22 to 38, wherein the pump system comprises a plurality of pumps and performs a flow stop step which includes stopping one or more of the plurality of pumps.

[0125] Embodiment 40. The method according to any one of Embodiments 22 to 39, wherein the valve system comprises a plurality of clamps and performs a flow stop step which includes closing one or more of the plurality of clamps.

[0126] Embodiment 41. The method according to any one of Embodiments 22 to 40, wherein the selected relative centrifugal force is between approximately 10G and approximately 1450G.

[0127] Embodiment 42. The method according to any one of Embodiments 22 to 41, wherein the selected relative centrifugal force is between approximately 100G and approximately 1140G.

Claims

1. 1. A blood processing apparatus comprising: A pump system; a valve system; a centrifuge; a control unit; The control unit performing a priming step in which the pump system and the valve system are controlled to prime a processing chamber located within the centrifuge; performing a blood separation step in which the pump system, the valve system, and the centrifuge are controlled to separate the blood in the processing chamber into at least two blood components; performing a blood component collection step in which the pump system and the valve system are controlled to collect at least a portion of one of the at least two blood components; performing a flow stop step that interrupts at least one of the priming step, the blood separation step, and the blood component collection step; The flow rate stopping step comprises: (i) controlling the pump system and the valve system to prevent fluid flow into and out of the processing chamber; (ii) controlling the centrifuge at a selected speed and / or a selected relative centrifugal force; (iii) terminating the flow stop phase after a selected time; (iv) resuming the interrupted step after terminating said flow stop step or proceeding with a subsequent step of the blood separation procedure.

2. The blood processing device described in claim 1, wherein the control unit is configured to execute the flow rate stopping step so as to prevent any of the priming step, the blood separation step, and the blood component collection step.

3. 3. The blood processing apparatus of claim 1, wherein the blood comprises whole blood, and the at least two blood components comprise red blood cells and plasma.

4. 3. The blood processing device of claim 1 or claim 2, wherein controlling the centrifuge at a selected speed during the flow stop phase comprises rotating at a speed between 500 RPM and 5500 RPM.

5. 3. The blood processing device of claim 1 or claim 2, wherein controlling the centrifuge at a selected speed during the flow stop phase comprises rotating at a speed of about 1500 RPM, about 3500 RPM, or about 5000 RPM.

6. 3. The blood processing device of claim 1 or claim 2, wherein the selected time for the flow stop phase is comprised between 15 seconds and 45 seconds.

7. 3. The blood processing device of claim 1 or claim 2, wherein the selected time period of the flow stop phase comprises approximately 30 seconds.

8. The step of collecting blood components further comprises: (i) transferring whole blood from the blood source to the processing chamber until a total quantity of one unit of whole blood is transferred from the blood source to the processing chamber; 4. The blood processing apparatus of claim 3, further comprising: (ii) controlling the centrifuge to separate the whole blood in the processing chamber into plasma and red blood cells; transporting the separated plasma from the processing chamber to a plasma collection container; removing the separated red blood cells from the processing chamber; removing an additive solution from an additive solution container of a fluid flow circuit; and combining the separated red blood cells and the additive solution as a mixture and transferring it into a red blood cell collection container of the fluid flow circuit.

9. 10. The blood processing device of claim 8, further comprising performing an additive solution flush step in which additive solution is transferred from the additive solution container to the red blood cell collection container using the pump system and the valve system until a target amount of additive solution is transferred into the red blood cell collection container.

10. 9. The blood processing device of claim 8, wherein the fluid flow circuit includes a whole blood container containing a unit of whole blood, and the blood source is the whole blood container.

11. performing the blood component collection step, weighing the whole blood container; and terminating the blood component collection step based at least in part on the weight of the whole blood container.

12. The blood processing device of claim 11, wherein the blood source is a living donor.

13. Performing the blood component collection step further comprises: measuring the hydrostatic pressure of the whole blood container; and terminating the blood component collection step based at least in part on the hydrostatic pressure of the whole blood container.

14. performing the blood component collection step, 10. The blood processing device of claim 8, further comprising, during at least a portion of said blood component collection step, conveying said mixture through a leukocyte reduction filter prior to delivery to said red blood cell collection container.

15. 4. The blood processing device of claim 3, wherein said priming step comprises transporting whole blood from a blood source to a processing chamber to remove air from said processing chamber.

16. Performing the priming step comprises: monitoring fluid exiting the processing chamber; 3. The blood processing system of claim 1, further comprising terminating said priming step when non-air fluid is detected exiting said processing chamber.

17. 4. The blood processing device of claim 3, wherein the blood separation step comprises removing the plasma and the red blood cells from the processing chamber, recombining the plasma and the red blood cells as recombined whole blood, and introducing the recombined whole blood into the processing chamber.

18. 3. The blood processing device of claim 1, further comprising performing an air flush step using the pump system and the valve system to deliver air to the processing chamber to transport at least one of the separated blood components from the processing chamber.

19. 3. The blood processing device of claim 1 or claim 2, wherein the pump system comprises a plurality of pumps, and wherein the flow stopping step comprises stopping one or more of the plurality of pumps.

20. 3. The blood processing device of claim 1 or claim 2, wherein the valve system comprises a plurality of clamps, and performing a flow stop step includes closing one or more of the plurality of clamps.

21. 3. The blood processing device of claim 1 or claim 2, wherein the selected relative centrifugal force is between about 10 G and about 1450 G.

22. 3. The blood processing device of claim 1 or claim 2, wherein the selected relative centrifugal force is between about 100 g and about 1140 g.

23. 1. A method for separating whole blood, comprising: performing a priming step in which a pump system and a valve system of the blood processing device are controlled to prime a processing chamber disposed within a centrifuge of the blood processing device; performing a blood separation step in which the pump system, the valve system, and the centrifuge are controlled to separate the blood in the processing chamber into at least two blood components; performing a blood component collection step in which the pump system and the valve system are controlled to collect at least a portion of one of the at least two blood components; performing a blood separation procedure, the blood separation procedure comprising: performing a flow stop step that interrupts at least one of the priming step, the blood separation step, and the blood component collection step; The flow rate stopping step comprises: (i) controlling the pump system and the valve system to prevent fluid flow into and out of the processing chamber; (ii) controlling the centrifuge at a selected speed and / or a selected relative centrifugal force; (iii) terminating the flow stop phase after a selected time; (iv) resuming the interrupted step after terminating the flow stop step or proceeding with a subsequent step of the method.

24. 24. The method of claim 23, wherein the blood comprises whole blood and the at least two blood components comprise red blood cells and plasma.

25. 25. The method of claim 23 or claim 24, wherein controlling the centrifuge at a selected speed during the flow stop phase comprises rotating at a speed between 500 RPM and 5500 RPM.

26. 25. The method of claim 23 or claim 24, wherein controlling the centrifuge at a selected speed during the flow rate stopping phase comprises rotating at a speed of about 1500 RPM, about 3500 RPM, or about 5000 RPM.

27. 25. The method of claim 23 or claim 24, wherein the selected time for the flow stop phase is comprised between 15 seconds and 45 seconds.

28. 25. The method of claim 23 or claim 24, wherein the selected time period of the flow stop phase comprises about 30 seconds.

29. The step of collecting blood components further comprises: (i) transferring whole blood from the blood source to the processing chamber until a total quantity of one unit of whole blood is transferred from the blood source to the processing chamber; 25. The method of claim 24, including: (ii) controlling the centrifuge to separate the whole blood in the processing chamber into plasma and red blood cells; transporting the separated plasma from the processing chamber to a plasma collection container; transporting the separated red blood cells from the processing chamber; transporting an additive solution from an additive solution container of a fluid flow circuit; and combining the separated red blood cells and the additive solution as a mixture and transporting it into a red blood cell collection container of a fluid flow circuit.

30. 30. The method of claim 29, further comprising performing an additive solution flush step in which additive solution is transferred from the additive solution container to the red blood cell collection container using the pump system and the valve system until a target amount of additive solution is transferred into the red blood cell collection container.

31. 30. The method of claim 29, wherein the fluid flow circuit includes a whole blood container containing a unit of whole blood, and the blood source is the whole blood container.

32. performing the blood component collection step, weighing the whole blood container; and terminating the blood component collection step based at least in part on the weight of the whole blood container.

33. 33. The method of claim 32, wherein the blood source is a living donor.

34. Performing the blood component collection step further comprises: measuring the hydrostatic pressure of the whole blood container; and terminating the blood component collection step based at least in part on the hydrostatic pressure of the whole blood container.

35. performing the blood component collection step, 30. The method of claim 29, comprising conveying the mixture through a leukocyte reduction filter prior to entry into the red blood cell collection container during at least a portion of the blood component collection step.

36. 25. The method of claim 24, wherein the priming step comprises transporting whole blood from the blood source to the processing chamber to remove air from the processing chamber.

37. Performing the priming step comprises: monitoring fluid exiting the processing chamber; 25. The method of claim 23 or claim 24, comprising terminating the priming step when non-air fluid is detected exiting the process chamber.

38. 26. The method of claim 25, wherein the blood separation step includes removing separated plasma and red blood cells from the processing chamber, recombining the plasma and red blood cells as recombined whole blood, and introducing the recombined whole blood into the processing chamber.

39. 25. The method of claim 23 or claim 24, further comprising performing an air flush step using the pump system and the valve system to deliver air to the processing chamber to transport at least one of the separated blood components from the processing chamber.

40. 25. The method of claim 23 or claim 24, wherein the pump system comprises a plurality of pumps, and performing a flow stopping step comprises stopping one or more of the plurality of pumps.

41. 25. The method of claim 23 or claim 24, wherein the valve system comprises a plurality of clamps, and performing a flow stopping step comprises closing one or more of the plurality of clamps.

42. 25. The method of claim 23 or claim 24, wherein the selected relative centrifugal force is between about 10 G and about 1450 G.

43. 25. The method of claim 23 or claim 24, wherein the selected relative centrifugal force is between about 100 G and about 1140 G.

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